Friday Mail Sack: Shut Up Laura Edition

Hello again folks, Ned here for another grab bag of questions we’ve gotten this week. This late posting thing is turning into a bad habit, but I’ve been an epileptic octopus here this week with all the stuff going on. Too many DFSR questions though, you guys need to ask other stuff!

Question

Is it possible to setup a DFSR topology between branch servers and hub servers, where the branches are an affiliate company that are not a member of our AD forest?

Answer

Nope, the boundary of DFSR replication is the AD forest. Computers in another forest or in a workgroup cannot participate. They can be members of different domains in the same forest. In that scenario, you might explore scripting something like:

robocopy.exe /mot /mir<etc>

Question

I was examining KB 822158 – with the elegant title of “Virus scanning recommendations for Enterprise computers that are running currently supported versions of Windows” – and wanted to make sure these recommendations are correct for potential anti-virus exclusions in DFSR.

Answer

They better be, I wrote the DFSR section! 🙂

Question

Is there any way to tell that a user’s password was reset, either by the user or by an admin, when running Win2008 domains?

Answer

Yes – once you have rolled out Win2008 or R2 AD and have access to granular auditing, this becomes two easy events to track once you enable the subcategory User Account Management:

ID

Message

4723

An attempt was made to change an account’s password.

4724

An attempt was made to reset an account’s password.

Once that is turned on, the 4724 event tells you who changed who’s password:

And if you care, the 4738 confirms that it did change:

If a user changes their own password, you get the same events but the Subject Security ID and Account Name change to that user.

Remember that we don’t do developer support here on AskDS so you should direct your questions over to the AD PowerShell devs if you get stuck in code specifics.

Question

Is their any guidance around using DFSR with satellite link connections?

Answer

Satellite connections create a unique twist to network connectivity – they often have relatively wide bandwidth compared to low-end WAN circuits, but also have comparitively high latency and error levels. When transmitting a packet through a geosynchronous orbit hop, it hits the limitation of the speed of light – how fast you can send a packet 22,000 miles up, down, then reply with a packet up and down again. And when talking about a TCP conversation using RPC, one always uses round trip times as part of the equation. You will be lucky to average 1400 millisecond response times with satellite, compared to a frame relay circuit that might be under 50ms. This also does not account for the higher packet loss and error rates typically seen with satellite ISP’s. Not to mention what happens when it, you know, rains :-). In a few years you can think about using medium and low earth orbit satellites to cut down latency, but those are not commercially viable yet. The ones in place have very little bandwidth.

When it comes to DFSR, we have no specific guidance except to use Win2008 R2 (or if you must, Win2008) and not Win2003 R2. That first version of DFSR uses synchronous RPC for most communications and will not reliably work over satellite’s high latency and higher error rates – Win2008 R2 uses asynchronous RPC. Even Win2008 R2 may perform poorly on the lower bandwidth ranges. Make sure you pre-seed data and do not turn off RDC on those connections.

Other

Totally unrelated, I found this slick MCP business card thing we’re doing now since we stopped handing out the laminates. It’s probably been around for a while now, but hey, new to me. 🙂 If you go to https://www.mcpvirtualbusinesscard.com and provide your MCP ID # and Live ID you can get virtual business cards that link to your transcript.

Then you can have static cards:

Or get fancy stuff like this javascript version. Mouse over the the right side to see what I mean:

Oh yeah, did you know my name is really Edward? They have a bunch of patterns and other linking options if you don’t want graphics; give it a look.

Tags

Whilst I don't doubt 2K8R2 DFS-R is better, I have used DFS-R extensively over satellite services. I work in mining with sites all over the 3rd world jungles. Satellite is often the only way in and out. Often these are skinny due to crazy 3rd world legislation over carriers. I first used DFS-R over a 386kb satellite link in 2005 that was the primary corporate link shared with web and email (1500 users). It was used there to replicate the Exec home drives to / from civilisation. I can firmly say it works, and works very well, even without 2K8R2. It's a very robust technology, even on links that are hammered with load and high latency.